docs: def point_distance_ellipsode(point1,point2):
      """
      calculate the distance between two points on the ellipsode based on point1
      
      Keyword arguments:
      point1  -- point one geojson object
      point2  -- point two geojson object
      
      return distance
      """
      a = 6378137
      f = 1/298.25722
      b = a - a*f
      e = math.sqrt((a*a-b*b)/(a*a))
      lon1 = point1['coordinates'][0]
      lat1 = point1['coordinates'][1]
      lon2 = point1['coordinates'][0]
      lat2 = point2['coordinates'][1]
      M = a*(1-e*e)*math.pow(1-math.pow(e*math.sin(number2radius(lat1)),2),-1.5)
      N = a/(math.pow(1-math.pow(e*math.sin(number2radius(lat1)),2),0.5))
      
      distance_lat = M*number2radius(lat2-lat1)
      distance_lon = N*math.cos(number2radius(lat1))*(lon2-lon1)*3600*math.sin(1/3600*math.pi/180)
      return math.sqrt(distance_lat*distance_lat+distance_lon*distance_lon)